1. Field
The invention(s) relate to optical communication equipment and, more specifically but not exclusively, to equipment for managing data transport through a noisy optical channel.
2. Description of the Related Art
This section introduces aspects that may help facilitate a better understanding of the invention(s). Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.
Forward error correction (FEC) uses systematically generated redundant data to reduce the bit-error rate (BER) at the receiver. The cost of this reduction is a concomitant increase in the required forward-channel bandwidth, with the latter being dependent on the data rate of the FEC code. In general, an FEC code with a lower payload data rate is used for a noisier channel. When the channel conditions fluctuate over time, the data rate and/or the FEC code can be adaptively changed to maintain an acceptable BER. However, one problem with FEC coding, as applied to optical transport systems, is that the coding-gain differences among various implementable FEC codes usually do not exceed a certain maximum value, as given by Shannon's information theory. Therefore, for certain optical channels, additional and/or alternative performance-enhancement techniques may be needed to overcome these and other pertinent limitations of FEC coding.